Increased colonic motility in a rat model of irritable bowel syndrome is associated with up-regulation of L-type calcium channels in colonic smooth muscle cells

M. Zhang, Fung Ping LEUNG, Y. Huang*, Zhaoxiang BIAN

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)

Abstract

Objective This paper aimed to investigate the relationship between up-regulation of L-type calcium channels and altered motility disorder in a rat model of irritable bowel syndrome (IBS). Methods Male Sprague-Dawley rats were subjected to neonatal maternal separation (NMS) from postnatal day 2-14 or normal handling (NH), and used when weighted 250-300 g. Colonic smooth muscle contractions was studied in an organ bath system. L-type Ca2+ channel α1c subunit expression in smooth muscles from rat colon were studied by immunofluorescence and Western blotting analysis. The intracellular calcium concentration ([Ca2+]i) of enzymatically isolated single colonic smooth muscle cell was studied with laser confocal fluorescent microscopy. Results The fecal pellets during 1 h water avoidance stress (WAS) were significantly increased; the amplitude of spontaneous contractions and contractions induced by Bay K 8644 (10 nm-1 μm), KCl (10-60 mm) and ACh (100 nm-10 μm) were significantly increased in NMS rats, when comparing with that of NH rats. [Ca2+]i induced by Bay K 8644 (1 μm), KCl (40 mm), and ACh (10 μm) significantly increased in muscle cells of NMS rats than NH rats. Further, α1c protein expression was significantly up-regulated in colonic smooth muscle of NMS rats than NH rats. Conclusion These results suggest that NMS lead to up-regulation of L-type Ca2+ channels expression in the colon, which contributes to the colonic motility disorder. Our findings provide direct evidence to help understanding the underlying mechanism of chronic stress-induced colonic motility disorder in IBS.

Original languageEnglish
Pages (from-to)e162-e170
JournalNeurogastroenterology and Motility
Volume22
Issue number5
DOIs
Publication statusPublished - May 2010

Scopus Subject Areas

  • Physiology
  • Endocrine and Autonomic Systems
  • Gastroenterology

User-Defined Keywords

  • Irritable bowel syndrome
  • L-type Ca channel
  • Motility disorder
  • Neonatal maternal separation

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